Agreed Don...
the Vehicle manufacturers recommendation is to use SG 10W30
earlier i could not find any oil witn SG specification, so i used SL 10W30
But now it is not available, now it is SN/CF 10W30
cuz i know 10W30 stands for 0'c viscosity of 10, and running temperature viscosity of 30 (Correct me if i am wrong)
but i do not know what they meant by the letters,
so i wanted to know is what does the manufacturer meant by SG,SL or SN/CF. is there a real difference in that.